In the research project MOVE, ARC is investigating methods and systems to estimate the environmental impact of road traffic. The project is financed by the Norwegian Research Council, through the BIA program. MOVE is managed by Acoustic One/Norsonic AS and SINTEF; other partners are NTNU and Norsk Elektro Optikk AS (NEO). The project started in 2012 and will be finished in 2015.
In the project, we are focusing on methods to measure the noise from individual vehicles in a traffic stream. This is important for several reasons:
- It is possible to measure the effect of more stringent noise levels for different classes of vehicles and more stringent noise levels for tyres
- It is possible to measure the effect of changing a road surface (measurements according to an ISO standard)
- It is possible to evaluate which classes of vehicles are the main contributors to the overall traffic noise level
- It is possible to study the variation in noise levels depending on vehicle speed and meteorological condition (temperature, road wetness, wind, etc.)
In addition to noise levels, the project are also testing out a laser based system developed by NEO where the amount of carbon monoxide of a passing vehicle is measured.
In a dense traffic situation, it is not possible to separate acoustically individual vehicles. In order to be able to do measurements under such conditions, a microphone array has been developed. Using 6 microphones, it has been shown by simulations, that it is possible to separate two vehicles acoustically even if the vehicles are separated with only a few meters, and at speeds around 80-100 km/h. The picture above the microphone array currently under test.
The acoustical system from Norsonic AS is based on their new precision sound and vibration analyser NOR150. To measure the speed of the vehicle, the lane position, and the category of vehicle, a commercial available system called TOPO.BigBox from RTB GmbH in Germany has been bought for the project. A prototype of the system is currently being tested out at a special test site south of Trondheim (E6, Klett).
The measured sound levels at the monitoring station will also be made available on a website. The presentation of the results shall be made in a simple way to make it as understandable for the general public as possible.